Inductors implemented in a circuit are susceptible to coupling from external magnetic fields. The external magnetic fields may originate from other components within the circuit and/or may alternatively arise from an external source. Coupling of external magnetic fields is a form of electromagnetic interference and can negatively impact the performance of the circuit.
A radio frequency (RF) transceiver is a type of wireless transceiver comprising circuitry that enables both transmitting and receiving of RF signals. An oscillator circuit is used to generate an RF signal for the RF transceiver. An RF transceiver may be implemented in an integrated circuit (IC) on a chip.
An oscillator circuit may comprise inductors. For example, FIG. 1(a) shows a schematic of a tiny quadrature oscillator circuit, herein referred to as a quadrature oscillator circuit 100, comprising four class-D amplifiers of the type shown in FIG. 1(b), where each class-D amplifier comprises an inductor (Massoud Tohidian et. al., A Tiny Quadrature Oscillator Using Low-Q Series LC Tanks, IEEE Microwave and Wireless Components Letters, Vol. 25, No. 8, August 2015). The inclusion of inductors means that the quadrature oscillator circuit 100 is susceptible to magnetic coupling. Additionally, inductors can occupy a large area on the chip.